CAT \PHR ACTA. 



of their feet ; but after careful study, I have been induced 

 to distribute them into two leading divisions, as proposed by 

 M. Latreille, and to subdivide ihese into six orders. 



Sjjnopsis Ordinum et Familianim. 



Sect. I.— CATAPHRACTA-. lingua brevis adnata; or- 

 gsna generationis simplicia ; ossa quadrata in cranio inclusa. 



Fam. 1. Chelonii : vertebrae dorsi costse et sternum ag- 

 gli.tinata immobilia, fornicem dorsalem sternalemque for- 

 mantia ; os edentulum rostratum. 



Fam. 2. Emydosauri: vertebrae dorsi et costae mobiles 

 liberae; os dentatum; pedes digitati. 



? Fam. 3. Ichthvosauki : vertebrae dorsi et costae mobiles 

 liberae; os dentatum ; pedes pinnilormes. 



Sect. I[. SQUAMATA : lingua libera; organa genera- 

 tionis duplicia ; ossa quadrata e cranio discreta. 



Fam. 4. Saurt : os non dilatabile ; cutis squamis variis 

 inaequalibus tecta. 



Fam. 5. Ophiosauri : os non dilatabile ; cutis squamis 

 aequalibus similibus tecta. 



Fam. 6. Ophidii : os dilatabile ; ossa mastoidea e cranio 

 discreta ; pedes nulli. 



Sect. 1. CATAPHRACTA, Latr. 



Lingua brevis adnata ; organa generationis simplicia; anus 

 longitudinalis vel rotundus ; ossa quadrata et pterygoidea in 

 cranio affixa. 



The reptiles of this division, which was originally proposed 

 by M. Latreille, are distinguished by their tongues being 

 very short and affixed to the sides of the mouth, so that they 

 can scarcely be exserted. The males have a single penis and 

 the females a single vagina, like most other vertebrated 

 animals. Their vent is either a longitudinal slit or a round- 

 ish hole. The quadrate bone and the pterygoid processes are 

 included in and form part of the skull. The limbs and tail 

 are covered with large bony scales, and the body is either 

 protected by two shields, formed by the union of the ver- 

 tebrae, ribs, and sternum into a bony case, and covered with a 

 cartilaginous or horny skin, or by longitudinal rows of bony 

 plates inserted in the skin, and covered with an epidermis- 



